The number of signal sources for television receivers has increased in recent years to include not only broadcast signals, but also, signals from videocassette recorders (VCRs), videodisc players, and cable converter units. As a result of this variety of signal sources, the selection of operating parameters for television receivers has become increasingly more complex. For example, the RF modulators of VCRs and videodisc players are generally programmable to provide their signals in the channel 3 or channel 4 frequency range to allow the user to select whichever of channel 3 or 4 is unused by broadcasters in his local area. Thus, the television receiver must be tuned to the preselected output channel in order to receive VCR or videodisc signals.
As another example of how the operating parameters of the television receiver should accommodate the signal source consider that in many instances, viewers use the RF tuner in their VCR to select channels for viewing, rather than using the tuner on their television receiver because, for example, the VCR may have remote control capability, and the television receiver may not. Similarly, cable converter units generally remodulate received broadcast and cable channel frequencies to a predetermined television channel, usually channel 2, 3, or 4. Some cable converters now in use, for example, M/A-COM Model 3025, allow remote control of the volume as well as remote control of channel selection. In order to make full use of this feature, the volume control of the television receiver must be turned fully on. However, other cable converters do not include this feature, requiring that volume control be accomplished via the television receiver volume control. Because the choice of these operating parameters is dictated primarily by the type of equipment connected to the television receiver, and by the channels available in the local broadcasting area of the viewer, presetting of these operating parameters at the factory is not feasible. Therefore, an "in-home parameter set-up" of the television receiver must be performed by the user. This may entail: turning on the receiver, selecting the proper channel, adjusting the volume control at the television receiver. In addition, some television receivers include scanning the range of channels and storing information relating to active channels encountered during the scan in a preferred channel memory. Automatic activation of this feature may be undesirable if the user's television receiver is connected to a signal source which provides television signals on a single channel only However, an automatic initialization of the autoprogramming feature may be desirable to those viewers whose television receivers are coupled to an antenna, for example. Therefore the in-home parameter set-up may also include initializing autoprogramming of the television receiver's preferred channel memory.
For those viewers whose television receivers include a mechanical tuner, a mechanical on/off switch, and a volume control potentiometer, the in-house set-up of the operating parameters need only be performed once, because the above-listed mechanical components retain their respective settings when power is interrupted.
Many modern television receivers are controlled electronically via a keyboard or remote control. These receivers rely on non-volatile memory, or volatile memory maintained by a standby power supply, to retain the last channel data and last volume setting data required as operating parameters for their particular television system. Standby power supplies are commonly used in televisions using volatile memories for maintaining the preferred channel list when the receiver is turned off. Standby power supplies are also used when the television receiver includes a remote control unit because the remote control unit must be continuously active in order to receive and process a TV-ON command. However, because standby power is dependent upon the AC power delivered to the television receiver, it is subject to interruption when the AC power fails. If the AC power fails for a period greater than the discharge time of the capacitors in the standby power supply, the data in the volatile memory devices of the receiver will be lost, requiring reprogramming of these parameters by the user after power returns.
Some cable converter units include a switched AC power outlet for supplying AC power to a television receiver, enabling the receiver to be turned on and off under remote control via the cable converter unit. However, this is only possible with receivers which have a manual on-off switch and not with receivers which have an electronic on-off switch. Thus, to use the remote control of the cable converter, for an electronically controlled television, a user must first cause the television to be turned on. In addition, as stated above, many modern television receivers have electronic tuning rather than mechanical tuning, and when power is first applied, those receivers automatically tune to a particular channel, usually channel 2. A television which automatically tunes to a channel other than the output channel of the cable converter unit connected to it, causes the annoyance that the user must retune the television receiver.
U.S. Pat. No. 4,651,342 (Mengel), issued 17 Mar. 1987 to the present inventor, discloses an auxiliary control unit for a television receiver which senses the development of standby power, automatically turns on the receiver, and automatically tunes the receiver to a a programmable initial channel. As stated above, however, it may not be desirable to provide the function of auto turn-on in some instances, and while the reference discloses forcing the tuner to a particular channel, no provision is disclosed for adding that channel in a preferred channel memory, or automatically initiating an autoprogramming function.
An additional problem is confronted when a television is coupled with a cable converter unit in a hotel/motel environment. A guest, who may be unfamiliar with the particular cable television system of the institution, may inadvertently change channels at the television receiver rather than via the cable converter unit and, thereby detuning the television receiver from its required channel, and losing signal reception capability. As a result, the guest may become confused, erroneously believing the system to be faulty, and may generate a needless service call.